All efforts of forced feeding him failed, Sir Ganesh Dutt, the then minister of Bihar, asked Singh's mother, Daulat Kuer, to attend to urge him to give up his fast. When she attended, on the 50th day of the fast, she blessed him. People waited daily at the jail gate to receive Singh's body should he die. All political prisoners in the jail were also on fast for the last few days in solidarity with him but on the 58th day he broke his fast after being informed by Gandhi that his demands had been met. He was released from jail in June 1936 because of his poor health but the city act was imposed on him to restrict his movement. He violated the restrictions and was again arrested. Singh studied subjects such as history, geography, political science, philosophy, social sciences and natural sciences during his imprisonments. He had a photographic memory. Politics and trade union work Singh was active in the trades union movement from 1936 until his death in 1989. He joined the Congress Socialist Party in December 1936 and was appointed its labour secretary. He established trade unions in the coal fields, sugar mills, mica mines and railways of Bihar. He formed Japla labour union in 1937, Baulia Labour union in 1937, organised the workers of Jamalpur Workshop along with Shivnath Bannerjee, formed the Gaya cotton and Jute Mill Labour Union, formed the Tata Collieries Labour Association along with Subhas Chandra Bose and went on to become the latter organisation's president when Bose left India in 1941. He organised coal workers of Talcher with close co-ordination and support of Dukhabandhu Mishra (founder member of HMS union in Talcher coalfields), Rajgangpur (Orissa) and Satna (MP); established Mica Workers Union, Gomia Labour Union (Explosives), later these unions affiliated to HMS. He was active in AIRF from 1936, president of OT Railway Union from Agra to Nefa and NE Railway Mazdoor Union. He was rearrested in April 1937 along with Jayaprakash Narayan, Benipuri and others in Patna for "unconstitutional" works for six months. During the Second World War he was the first man in Bihar to be arrested under Defence of India Ordinance on 26 January 1940 in Husainabad, Palamu and released after eighteen months. During the Quit India Movement, after the interception of Jayaprakash Narayan's Deoli letter addressed to him, he went underground in 1941 and went to Afghanistan